Simulated aging of draught beer line tubing increases biofilm contamination.

Craft brewing is continually gaining popularity in the United States. Craft brewers are committed to producing a wide variety of products and have a vested interest in product quality. Therefore, these brewers have the expectation that the beer poured at the tap will match the quality product that left the brewery. The presence of biofilm in draught lines is hypothesized as a contributing factor when this expectation is not achieved. Clean in place strategies based on the Sinner's Circle of Cleaning are used to remediate organic and inorganic accumulation in beer draught lines, including controlling biofilm accumulation. A study was conducted to determine if repeated exposure to chemical cleaning of vinyl beer tubing impacted biofilm growth, kill/removal, and subsequent regrowth of a mixed species biofilm. The tubing was conditioned to simulate one, two, and five years of use. The data collected demonstrates a clear trend between simulated age of the tubing and biofilm accumulation on the surface. Bacterial log densities ranged from 5.6 Log10(CFU/cm2) for the new tubing to 6.6 Log10(CFU/cm2) for tubing aged to simulate five years of use. The counts for the yeast were similar. Caustic cleaning of the tubing, regardless of starting biofilm coverage, left less than 2.75 Log10(CFU/cm2) viable bacteria and yeast cells remaining on the tubing surface. This demonstrated the effectiveness of the caustic at controlling biofilm accumulation in the simulated beer draught line. The biofilm that accumulated in the five-year aged tubing was able to recover more quickly, reaching 3.6 Log10(CFU/cm2) within 24 h indicating the treatment did not fully eradicate the biofilm, suggesting that the strong chemistry used in this study would cease to be as effective over time.

Harnessing active biofilm for microbial corrosion protection of carbon steel against Geobacter sulfurreducens.

Microbiologically influenced corrosion (MIC) caused by corrosive microorganisms poses significant economic losses and safety hazards. Conventional corrosion prevention methods have limitations, so it is necessary to develop the eco-friendly and long-term effective strategies to mitigate MIC. This study investigated the inhibition of Vibrio sp. EF187016 biofilm on Geobacter sulfurreducens on carbon steel. Vibrio sp. EF187016 biofilm reduced the corrosion current density and impeded pitting corrosion. A thick and uniform Vibrio sp. EF187016 biofilm formed on the coupon surfaces, acting as a protective layer against corrosive ions and electron acquisition by G. sulfurreducens. The pre-grown mature Vibrio sp. EF187016 biofilms, provided enhanced protection against G. sulfurreducens corrosion. Additionally, the extracellular polymeric substances from Vibrio sp. EF187016 was confirmed to act as a green corrosion inhibitor to mitigate microbial corrosion. This study highlights the potential of active biofilms for eco-friendly corrosion protection, offering a novel perspective on material preservation against microbial corrosion.

Antibiofilm activity of electrochemically activated water (ECAW) in the control of Salmonella Heidelberg biofilms on industrial surfaces.

Owing to its antimicrobial activity, electrochemically activated water (ECAW) is a potential alternative to chemical disinfectants for eliminating foodborne pathogens, including Salmonella Heidelberg, from food processing facilities. However, their antibiofilm activity remains unclear. This study aimed to evaluate the antibiofilm activity of ECAW against S. Heidelberg biofilms formed on stainless steel and polyethylene and to determine its corrosive capacity. ECAW (200 ppm) and a broad-spectrum disinfectant (0.2%) were tested for their antibiofilm activity against S. Heidelberg at 25 °C and 37 °C after 10 and 20 min of contact with stainless steel and polyethylene. Potentiostatic polarization tests were performed to compare the corrosive capacity of both compounds. Both compounds were effective in removing S. Heidelberg biofilms. Bacterial counts were significantly lower with ECAW than with disinfectant in polyethylene, regardless the time of contact. The time of contact and the surface significantly influenced the bacterial counts of S. Heidelberg. Temperature was not an important factor affecting the antibiofilm activities of the compounds. ECAW was less corrosive than the disinfectant. ECAW demonstrated a similar or even superior effect in the control of S. Heidelberg biofilms, when compared to disinfectants, reducing bacterial counts by up to 5 log10 CFU cm-2. The corrosion of stainless steel with ECAW was similar to that of commercial disinfectants. This technology is a possible alternative for controlling S. Heidelberg in the food production chain.

Histopathological findings in a pilot study of dairy calves disbudded with hot cauterization or caustic paste.

We describe the histological tissue damage and compare the healing process in 16 dairy calves disbudded at a mean age of 6 days by cauterization or alkaline caustic paste application. Biopsies were taken 2 days (T2) and 2 weeks (T14) after disbudding from sedated calves treated with local anaesthetic and non-steroidal anti-inflammatory drugs. At T2, the cauterized horn buds generally had eosinophilic coagulative necrosis of the epidermis and superficial dermis, bordered basally by a neutrophilic demarcation zone. Lateral to the direct heat contact area, dermal blood vessels were thrombosed, with wall damage and perivascular neutrophils. In the caustic paste-treated horn buds, the epidermis and dermis had diffuse full-thickness liquefactive necrosis directly under the paste contact area. The necrosis spread laterally in the dermis beyond the area of paste contact and was bordered by a neutrophilic infiltrate. At T14, the cauterized horn buds had epidermal to superficial dermal ulceration and crusting, dermal neutrophilic infiltration and granulation tissue formation. In contrast, most of the caustic paste-treated horn buds consisted of a superficial dermal crust or predominantly necrotic tissue fragments. The remaining viable areas had histiocytic inflammation with peripheral neutrophils and early granulation tissue formation. Caustic paste disbudding caused poorly demarcated lesions that were more severe and extensive and took longer to heal than those due to cautery. Cauterization induced a more intense acute reaction adjacent to the primary lesion compared with caustic paste.

Microbial Corrosion in Orthodontics.

Even with the exponential popularity of the contemporary clear aligners, the main stream of orthodontic practice still remains to be metal braces especially in adolescent age-group.1 Along with the advantages of metal braces such as lower cost, reduced friction, etc., there goes the disadvantages such as corrosion possibility, reduced esthetics, etc. Corrosion of orthodontic appliances is a widely researched topic.2-5 It is surprising to learn that microbially induced corrosion (MIC) has not been addressed in orthodontic literature till date. Microbial corrosion is an interesting arena which requires knowledge of both corrosion science and microbiology. The microorganisms capable of corrosion include various bacteria, fungi, and algae. The most common among them which has been widely indicated in MIC are the bacteria belonging to the sulfur cycle especially the sulfate-reducing bacteria (SRB). The connecting knot with orthodontics is the reported prevalence of these SRB in the oral cavity. SRB is prevalent in healthy individuals,6,7 patients associated with periodontitis6-11 and patients with gastrointestinal issues.12-14 The prevalence of SRB in the oral cavity has a greater clinical implication since the SRB have been proven to cause corrosion of stainless steel.15-24 There is literature attributing SRB as a potential cause in periodontal diseases7-11 as well as gastrointestinal diseases such as ulcerative colitis, inflammatory bowel diseases, and Crohn's disease.12 With its presence in the healthy oral environment already reported in the previous studies,6,7,25,26 it further emphasizes the absolute need to be researching on its corrosion possibility in the intra oral environment. The genus generally found intraorally was Desulfovibrio and Desulfobacter10 which is commonly regarded as the most "opportunistic" and ubiquitous group of sulfate reducers.6,7 There is an interesting literature on the inhibition of Desulfovibrio spp. by human saliva, the reason being quoted as salivary nitrate and nitrite.14 The mechanism behind the antimicrobial action of nitrate and nitrite is that they increase the oxidative stress on the bacteria.27 However, concentrations of salivary nitrate vary depending on the food intake, endogenous production, and salivary flow rate.28,29 Despite there exist natural inhibitors, the prevalence in oral cavity is high, 22% in healthy and 86% in patients associated with periodontitis.7 There is a predilection for the bacteria to grow when favorable conditions exist. Biofilms is one such favorable medium for the growth of SRB. Paster et al.26 identified SRB in biofilms of patients associated with refractory periodontitis, periodontitis, acute necrotizing ulcerative gingivitis (ANUG), and also in healthy subjects. Biofilm is a surface film composed of organic and inorganic saliva components that are colonized with microorganisms in extracellular polymeric substances adsorbed on all surfaces in the oral cavity.30 The oral biofilm formation is a complex process involving interspecies aggregation, which is surrounded by a cohesive matrix, forms a complex structure which in turn facilitates anaerobic growth. It is the intrinsic nature of oral biofilms which make the survival of facultative anaerobes such as SRB in the oral cavity possible. Literatures31-35 report that there are increased biofilm formations in orthodontic patients due to increased retentive areas caused by the brackets, ligatures, wires, mini implants, force components, and archwires. Bacteria in dental plaque function as a metabolically, functionally, and physically integrated community.36 The study by Mystkowska et al.37 mentioned that biofilm per se play a critical role in corrosion process by forming corrosive microcells. With time-dependent association, the microbes in the biofilm, along with saliva acting as an electrolyte and components from food, causes a decreased pH in the areas immediately under the biofilms. The decreased pH along with a change of oxygenation releases metal oxides and hydroxides from the metal surface ultimately leading to the corrosion of metallic structures.37-41 The initial roughness also acts in a vicious form promoting more biofilm adherence and the process repeats causing more corrosion. With the biofilm itself serving to initiate and propagate corrosion, the increased prevalence of SRB in patients associated with orthodontics treatment all the more increases the possibility of MIC of orthodontic materials.

Synthesis of silver nanoparticles from Indian red yeast rice and its inhibition of biofilm in copper metal in cooling water environment.

The development of environmentally acceptable benign techniques using purely natural methods is a cost-effective procedure with long-term benefits in all areas. With this consideration, myco synthesized silver nano particles (AgNPs) were studied and it acted as an impending corrosion inhibitor in the environment. Initially, AgNPs were evaluated by physical and surface characterizations and this evidence demonstrated that RYRE's water-soluble molecules played an essential role in the synthesis of AgNPs in nano spherical size. The myco synthesized of AgNPs has showed an antibacterial activity against corrosive bacteria in cooling water system (CWS). Hence, the AgNPs were used in biocorrosion studies as an anticorrosive agent along with AgNO3 and RYRE was also checked. For this experiment, the copper (Cu) metal (CW024) which is commonly used was selected, the result of corrosion rate was decreased, and inhibition efficiency (82%) was higher in the presence of AgNPs in system IV. Even though, AgNO3 and RYRE had contributed significant inhibition efficiency on Cu at 47% and 61%, respectively. According to XRD, the reaction of AgNPs on Cu metal resulted in the formation of a protective coating of Fe2O3 against corrosion. EIS data also indicated that it could reduce the corrosion on the Cu metal surface. All of these findings point out the possibility that the myco-synthesized AgNPs were an effective copper metal corrosion inhibitor. As a result, we encourage the development of myco-synthesized AgNPs, which could be useful in the industrial settings.

Investigating the effects of environment, corrosion degree, and distribution of corrosive microbial communities on service-life of refined oil pipelines.

Although the potential corrosive microbial communities of the refined oil pipelines can cause pipeline failure which directly threatens on soil and water environment, few studies have been published in this field. Therefore, the long-distance on-site internal corrosion detection and high-throughput sequencing techniques were employed in this study to investigate the distribution shifts of the corrosive microbial communities on the inner wall of a refined oil pipeline and its impact on the internal corrosion. The microorganisms colonizing on the inner wall of the pipeline showed significant distribution differences between the axial direction of the relative elevation and radial direction of the cross-section. On the inner wall, the high diversity and the abundance of the corrosive microbial communities induced serious microbiologically influenced corrosion (MIC), while the chemical corrosion and the synergy of the corrosive microbial communities accelerated the internal corrosion of the refined oil pipeline. A corrosion zone model has been proposed, which divides the pipeline cross-section into the sediment, the water-oil interface, the gas-oil interface, and the oil fully immersed zones. Therefore, the relationships between the environment, corrosion degree, and distribution characteristics of the corrosive microbial communities in the pipeline were analyzed. This research exhibited the importance of the distribution characteristics of the corrosive microorganisms on the inner wall of the refined oil pipelines. Its internal corrosion behavior was accurately explored, while providing a basis for controlling the corrosive microbial communities.

Inhibition performances of graphene oxide/silver nanostructure for the microbial corrosion: molecular dynamic simulation study.

Steel is one of the mainly used materials in the oil and gas industry. However, it is susceptible to the marine corrosion, which 20% of the total marine corrosion is caused by microbiologically influenced corrosion (MIC). The economic and environmental impacts of corrosion are significant, and it is crucial to fight against corrosion in a proper sustainability context and environmental-friendly methods. In this study, the graphene oxide/silver nanostructure (GO-Ag) inhibitory effect on the corrosion of steel in the presence of sulfate reducing bacteria (SRB) was investigated, via weight loss (WL) and Tafel polarization measurements. Moreover, molecular dynamic (MD) simulations were performed to obtain a deep understanding of the corrosion inhibition effect of GO-Ag. GO-Ag showed a significant antibacterial effect at 80 ppm. Moreover, WL and Tafel polarization measurements illustrated a great inhibition efficiency, which reached up to 84% reduction of WL and 98% reduction of corrosion current density (Icorr) after 7 days of incubation with GO-Ag. Based on MD simulations, bonding energy reached to the larger value in the presence of GO-Ag, which indicated the ability of graphene oxide nanosheets to be adsorbed on the steel surface and prevent the access of corrosive agents to the steel surface. The radial distribution function (RDF) results implied distance between corrosive agent (water and SRB) and steel surface (Fe atoms), which indicated protection of the steel surface due to the effective adsorption of GO nanosheets through the active sites of the steel surface. The mean square displacement (MSD) result showed smaller displacement of the corrosive particles on the surface of steel, resulting that the GO-Ag molecules bonded with Fe molecules on the surface of steel.

Conditioned place aversion of caustic paste and hot-iron disbudding in dairy calves.

Cauterization by hot iron and application of caustic paste are 2 common methods of disbudding calves. In this study, we compared the affective experience of these 2 procedures on young dairy calves using conditioned place aversion. Male dairy calves (n = 14; 7 ± 2 d old) were disbudded by both thermal and chemical methods (1 horn bud at a time, 48 h apart). Calves received treatments in pens made visually distinct with either red squares or blue triangles on the walls. Calves were restricted to these treatment pens for 6 h following disbudding. For all treatments, calves received a sedative (xylazine, 0.2 mg/kg), local anesthetic (lidocaine, 5 mL), and analgesic (meloxicam, 0.5 mg/kg). Calves were then tested for conditioned place aversion at 48, 72, and 96 h after their last treatment. During tests, calves were placed in a neutral pen connected to both treatment pens where they had previously been disbudded. Time spent in each treatment pen was recorded until calves chose to lie down for 1 min (latency to lie down: 31.0 ± 8.6 min). During the first test (48 h after last disbudding), calves spent more time in the pen associated with hot-iron disbudding compared with what would be expected by chance (intercept: 73.5%, 95% CI: 56.5, 90.5) and fewer calves lay down in the caustic paste pen than in the hot-iron pen (3 vs. 10 lying events). No evidence of preference for the hot-iron pen was found in the following test sessions (72 and 96 h since last disbudding). These results suggest that calves initially remember caustic paste disbudding as a more negative experience than hot-iron disbudding, even with the use of sedation, local anesthesia, and analgesia.

Possible healing effects of Salvadora persica extract (MISWAK) and laser therapy in a rabbit model of a caustic-induced tongue ulcers: histological, immunohistochemical and biochemical study.

Caustic ingestion is a potentially detrimental event that can cause serious devastating damage on contact with tissues. Local exposure is associated with severe pain, swelling and ulceration. Caustics-induced oral ulcers can be painful enough to compromise the patient's quality of life. Treatment of oral ulcers is crucial in clinical practice. Albeit, some ulcers do not respond adequately to the conventional treatment. The current study was conducted to evaluate the potential healing effects of topical Salvadora persica (SP) extract, low-level laser (LLL) and high-level laser (HLL) therapies in a rabbit model of caustic-induced tongue ulcers and explore the underlying mechanisms. Fifty male rabbits with a caustic induced tongue ulcers were included in the study. Rabbits were equally divided into four groups: positive control (ulcer) group, SP, LLL and HLL groups in addition to the negative control (healthy) group. All treatments were given thrice weekly for 14 days. Results showed that acetic acid-induced tongue ulcers caused extensive structural tongue damage secondary to overexpression of apoptotic BAX, pathological angiogenesis indicated by VEGF overexpression, marked collagen fibers deposition as well as upregulation of tissue pro-inflammatory TNF-α and upregulation of tissue anti-inflammatory IL-10. The healing potential of topical SP, LLL and HLL therapy are mostly comparable. In conclusion, acetic acid-induced extensive tongue damage. Topical SP extract, LLL and HLL are equally effective therapies against caustics-induced tongue ulcers. However, we recommend SP extract, owing to its safety, non-invasiveness, availability and low cost.

Prion disease and recommended procedures for flexible endoscope reprocessing - a review of policies worldwide and proposal for a simplified approach.

Several guidelines recommend specific treatments for endoscopes, procedures of quarantine for endoscopes, or additional treatments for the endoscope washer disinfector (EWD) in suspected or confirmed cases of Creutzfeldt-Jakob disease (CJD) or variant CJD (vCJD) but vary in many details. This study therefore reviewed guidelines on reprocessing flexible endoscopes after use in patients with suspected or confirmed prion disease. In addition, a literature search was performed in Medline on prion, CJD, vCJD, chemical inactivation, transmission healthcare, epidemiology healthcare, concentration tissue human and endoscope. Thus far, no case of CJD or vCJD transmitted by flexible endoscope has been reported. In animals it has been shown that oral uptake of 0.1-5 g of bovine spongiform encephalopathy (BSE)-infected brain homogenate is necessary for transmission. The maximum prion concentration in other tissues (e.g., terminal ileum) is at least 100-fold lower. Automated cleaning of endoscopes alone results in very low total residual protein ≤5.6 mg per duodenoscopes. Recommendations vary between countries, sometimes with additional cleaning, use of alkaline cleaners, no use of cleaners with fixative properties, use of disinfectants without fixative properties or single-use disinfectants. Sodium hydroxide (1 M) and sodium hypochlorite (10,000 and 25,000 mg/L) are very effective in preventing transmission via contaminated wires implanted into animal brains, but their relevance for endoscopes is questionable. Based on circumstantial evidence, it is proposed to consider validated reprocessing as appropriate in the case of delayed suspected prion disease when immediate bedside cleaning, routine use of alkaline cleaners, no fixative agents anywhere prior to disinfection and single use brushes and cleaning solutions can be assured.

Evaluation of alternatives to cautery disbudding of dairy goat kids using physiological measures of immediate and longer-term pain.

We evaluated alternatives to cautery disbudding of goat kids using physiological measures of immediate and longer-term pain. Fifty Saanen doe kids were randomly assigned to 1 of 5 treatments (n = 10/treatment): (1) cautery disbudding (CAUT), (2) caustic paste disbudding (CASP), (3) liquid nitrogen disbudding (CRYO), (4) clove oil injected into the horn bud (CLOV), or (5) sham disbudding (SHAM). Serum cortisol and haptoglobin concentrations were measured from blood samples collected immediately before treatment (baseline) and at 15, 30, 60, and 120 min and then again at 6 and 24 h post-treatment. An infrared thermography camera was used to take images of the horn buds 24 h pre- and 24, 48, and 72 h post-treatment to measure skin temperature. Body weight was measured daily for 1 wk to assess weight change post-treatment. Images of the horn buds were taken at d 1, 2, and 7 and at 6 wk post-treatment to assess tissue damage and wound healing. Mean cortisol concentrations were elevated in CASP kids 1 h post-treatment relative to CAUT kids. Cortisol concentrations of CRYO kids were higher than those of CAUT kids 30 min post-treatment; concentrations for CLOV kids were similar to CAUT kids post-treatment. Mean haptoglobin concentrations were similar across treatments over time; however, CLOV kids had higher concentrations at 24 h post-treatment than all other treatments. Skin temperatures of CASP and CLOV kids were elevated relative to CAUT kids at all time points post-treatment, and all disbudded kids had skin temperatures above those of SHAM kids at 72 h post-treatment. Treatment did not influence weight gain. The CAUT kids had large, open wounds exposing bone; small scabs were still evident 6 wk post-treatment. The CASP kids had red and open, raw wounds that generated large eschars, apparent for up to 6 wk. The CRYO kids had closed, dry wounds initially, but over time lesions appeared that caused open wounds; small scabs were present 6 wk post-treatment. The CLOV kids had closed, dry wounds with blackened skin; healed skin and minimal scabs were present 6 wk post-treatment. Caustic paste and cryosurgical disbudding appeared to cause more pain compared with cautery disbudding; thus, these methods may not provide good alternatives to cautery disbudding. Clove oil appeared to cause a similar pain response as cautery disbudding and smaller wounds with earlier tissue repair; this method shows promise as an alternative to cautery disbudding.

The effect of ß receptor blockade through propranolol on corneal neovascularization.

PURPOSE: To evaluate the inhibitory effects of propranolol, a nonselective and lipophilic ß-adrenergic receptor blocker, on alkali-induced corneal neovascularization (NV). METHODS: Corneal NV was induced in 24 eyes of 24 Wistar rats using NaOH. Following alkali burn, animals were randomized into 4 groups according to topical treatment. Group I received 0.9% NaCl, Group II received preservative-free dexamethasone sodium phosphate 1 mg/mL, Group III received propranolol hydrochloride 1 mg/mL, and Group IV received 0.5 mg/mL propranolol hydrochloride drops twice a day for 7 days. The inhibitory effects of the drugs were compared as the percent areas of cornea covered by NV. Anti-vascular endothelial growth factor (VEGF) and anti-active caspase-3 immunostainings were also performed in corneal sections. RESULTS: The median percent area of corneal NV was 59% (40.3-65.6) in Group I, 25.5% (20.9-43.4) in Group II, 68.9% (36.7-78.0) in Group III, and 50.4% (42.2-63.3) in Group IV. Group III and IV did not show any difference in comparison to Group I. Group II showed a statistically significant smaller area of corneal NV compared with Group I, III, and IV (P=0.004 for each comparison). Anti-VEGF immunostaining was significantly less in Group II compared with the other groups. Anti-active caspase-3 immunostaining was not different among the treatment groups. CONCLUSIONS: Topical propranolol 1 or 0.5 mg/mL does not have a significant inhibitory effect on alkali-induced corneal NV in rats.

Severe ulceration with impaired induction of growth factors and cytokines in keratinocytes after trichloroacetic acid application on TRPV1-deficient mice.

Transient receptor potential vanilloid 1 (TRPV1) is a highly polymodal TRP channel activated by various stimuli, including capsaicin, heat and acids. TRPV1 expression can be detected widely but is highest in sensory neurons and its activation alerts the body to noxious signals via neurogenic pain. Although TRPV1 is reportedly localized in the epidermis, it remains unclear how TRPV1 is involved in the chemical peeling processes with cytotoxic acids. Therefore, in this study, the role of TRPV1 on the effects of trichloroacetic acid (TCA) peeling was assessed using TRPV1-deficient mice. Following the confirmation of TRPV1 expression in murine keratinocytes with reverse transcription-polymerase chain reaction and immunohistochemistry, the effects of TCA on TRPV1-deficient mouse skin were compared with those on wild-type mouse skin. Our results indicated that TRPV1 expression was not required for TCA-induced DNA damage, as shown by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, but was indispensable for the TCA-induced production of distinct growth factors and cytokines by keratinocytes. Ulceration after TCA peeling was actually more severe in the absence of TRPV1, suggesting that the TRPV1-mediated epidermal production of growth factors and cytokines affected the damaging and healing processes of TCA-peeled skin to induce rejuvenation.

Purification of native Argonaute complexes from the fission yeast Schizosaccharomyces pombe.

Small interfering (si) RNAs, produced by the RNA interference (RNAi)-mediated processing of long double-stranded (ds) RNAs, can inhibit gene expression by post-transcriptional or transcriptional gene silencing mechanisms. At the heart of all small RNA-mediated silencing lies the key RNAi effector protein Argonaute, which once loaded with small RNAs can recognize its target transcript by siRNA-RNA Watson-Crick base pairing interactions. In the fission yeast Schizosaccharomyces pombe, the formation of the epigenetically heritable centromeric heterochromatin requires RNAi proteins including the sole fission yeast Argonaute homolog, Ago1. Two distinct native Ago1 complexes have been purified and studied extensively, both of which are required for siRNA production and heterochromatin formation at the fission yeast centromeres. The purification and analysis of the Argonaute siRNA chaperone (ARC) complex and RNA-induced transcriptional silencing (RITS) complex have provided insight into the mechanism of siRNA-Ago1 loading and the cis recruitment of silencing complexes at fission yeast centromeres, respectively. These discoveries have been instrumental in shaping the current models of RNA-mediated epigenetic silencing in eukaryotes. Below, we describe the protocol used for affinity purification of the native Ago1 complexes from S. pombe.

Development of an animal model for endometrial ablation using trichloroacetic acid.

OBJECTIVE: To develop an animal model of endometrial ablation, and to evaluate the histologic effects of trichloroacetic acid (TCA) in the uterine cavity. DESIGN: Experimental prospective. SETTING: Department of gynecology. PATIENT(S): Thirty female adult rats. INTERVENTION(S): Animals were submitted to injection of TCA in one uterine horn and saline solution in the other. Group 1 was sacrificed the day after the procedure. Group 2 was sacrificed in phase of diestrus. Superficial epithelia of the endometrium, stromal thickness, endometrial glands, and myometrium thickness were compared among the uterine horns of the same rats of group 1. The same evaluation was performed in group 2. Endometrial regeneration was evaluated. MAIN OUTCOME MEASURE(S): Histologic effects. RESULT(S): In group 1, histologic parameters showed endometrial destruction on TCA injected uterine horn. In group 2, four rats died after the procedure, and six rats had no viable material. In the rest of the group, TCA-injected uterine horns showed endometrial destruction. Superficial epithelia of the endometrium and stromal thickness were similar between TCA uterine horn from groups. However, the number of endometrial glands was higher in group 1. CONCLUSION(S): The study developed an experimental model for endometrial ablation. TCA acid is a potent agent for endometrial ablation in rat model. No endometrial regeneration was observed after recovery of cycle.

Detecting cellulase penetration into corn stover cell walls by immuno-electron microscopy.

In general, pretreatments are designed to enhance the accessibility of cellulose to enzymes, allowing for more efficient conversion. In this study, we have detected the penetration of major cellulases present in a commercial enzyme preparation (Spezyme CP) into corn stem cell walls following mild-, moderate- and high-severity dilute sulfuric acid pretreatments. The Trichoderma reesei enzymes, Cel7A (CBH I) and Cel7B (EG I), as well as the cell wall matrix components xylan and lignin were visualized within digested corn stover cell walls by immuno transmission electron microscopy (TEM) using enzyme- and polymer-specific antibodies. Low severity dilute-acid pretreatment (20 min at 100 degrees C) enabled <1% of the thickness of secondary cell walls to be penetrated by enzyme, moderate severity pretreatment at (20 min at 120 degrees C) allowed the enzymes to penetrate approximately 20% of the cell wall, and the high severity (20 min pretreatment at 150 degrees C) allowed 100% penetration of even the thickest cell walls. These data allow direct visualization of the dramatic effect dilute-acid pretreatment has on altering the condensed ultrastructure of biomass cell walls. Loosening of plant cell wall structure due to pretreatment and the subsequently improved access by cellulases has been hypothesized by the biomass conversion community for over two decades, and for the first time, this study provides direct visual evidence to verify this hypothesis. Further, the high-resolution enzyme penetration studies presented here provide insight into the mechanisms of cell wall deconstruction by cellulolytic enzymes.

Chemosurgery with trichloroacetic acid for allergic rhinitis: evaluation of the efficacy in terms of inhibition of Th2 cell infiltration.

OBJECTIVE: To examine local inhibition of Th2 cell infiltration as the basis for demonstrating the superior clinical effect of trichloroacetic acid (TCA) treatment for allergic rhinitis. METHODS: Mirror-image sections of the inferior turbinate mucosae of both sides were obtained from 26 patients who underwent TCA treatment on one side because of the nasal anatomy status and who eventually underwent bilateral inferior turbinectomy because of failure of the TCA treatment. Th2 cell counts, defined as counts of cells positive for anti-CD4 antibody and anti-CKR4 antibody (double-positive cells) were obtained for comparison. The differences between the TCA-treated and non-TCA-treated mucosae were analyzed by Mann-Whitney's U test. RESULTS: Th2 cell infiltration was characteristically found just beneath the epithelium and in the periglandular areas. The mean count+/-standard deviation of Th2 cells was 4.96+/-2.72 cells/mm(2) in the TCA-treated mucosae and 12.03+/-7.19 cells/mm(2) in the non-treated mucosae, the difference being significant (p<0.01). CONCLUSION: TCA treatment induces inhibition of Th2 cell infiltration. This corroborates the suggestion that TCA treatment can inhibit local type I allergic reactions.

Pretreatment of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide enhances osteoblastic differentiation and slows proliferation of mouse preosteoblast cells.

BACKGROUND: Surface topography is important in the creation of a scaffold for tissue engineering. Chemical etching of poly(l-lactide-co-glycolide) with sodium hydroxide has been shown to enhance adhesion and function of numerous cell types. The authors investigated the effects of sodium hydroxide pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds on the adhesion, differentiation, and proliferation of MC3T3-E1 murine preosteoblasts. METHODS: MC3T3-E1 cells were seeded onto three-dimensional poly(l-lactide-co-glycolide) scaffolds with and without 1 M sodium hydroxide pretreatment. Cells were then cultured in osteogenic medium and harvested at varying time points for RNA extraction. Quantitative real-time reverse-transcriptase polymerase chain reaction was performed to measure mRNA expression of several osteogenic marker genes. In addition, cell numbers were determined at varying time points during the culture period. All experiments were performed in triplicate. RESULTS: Pretreatment of three-dimensional poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide resulted in statistically significant up-regulation of mRNA expression of alkaline phosphatase, bone sialoprotein, osteocalcin, and vascular endothelial growth factor during the first 10 days of culture. Histologic analysis demonstrated a striking increase in mineralized cell matrix deposition in the sodium hydroxide-treated group. Cell number was statistically higher in the sodium hydroxide-treated group immediately after cell seeding, suggesting improved adhesion. During the first 24 hours of culture, cells grew faster in the control group than in the sodium hydroxide-treated group. CONCLUSIONS: Chemical etching of poly(l-lactide-co-glycolide) scaffolds with sodium hydroxide strongly influences the behavior of MC3T3-E1 preosteoblasts in vitro by enhancing adhesion and differentiation and slowing proliferation. Sodium hydroxide treatment may represent a simple and inexpensive way of improving scaffolds for use in bone tissue engineering.

A nuclear magnetic resonance spectroscopy comparison of 3C trituration derived and 4C trituration derived remedies.

BACKGROUND: Trituration of base substances, commonly to the 3cH level, is the cornerstone of the homeopathic pharmaceutical process or insoluble solutions. Becker and Ehrler claim that trituration to 4cH gives a new, spiritual dimension to the homoeopathic medicine picture. AIM AND METHOD: This study sought to establish whether the claim that C4-derived potencies possess different physicochemical qualities to the homoeopathic medicines derived from a 3cH trituration is valid. All potencies were produced by hand according to the German Homoeopathic Pharmacopoeia (GHP). Five different samples were analysed using Nuclear Magnetic Resonance (NMR) Spectroscopy. RESULTS: The results indicated a significant difference between the 12cH samples of potassium dichromate (Kalium bichromicum) produced from 3cH and 4cH triturations. This was especially prominent in the chemical shift values of all four peaks and the relative integration levels of the H(2)O, OH and CH(3) peaks when comparing two sample groups. CONCLUSION: Trituration plays a part in the development of physicochemical properties specific to homoeopathic medicines. The higher the level of trituration, the more pronounced is the alteration of the physical structure of the active ingredient. The study concludes that 4cH potencies are physicochemically distinct from 3cH-derived potencies (as currently employed).